If the NATO Warsaw summit is remembered for anything, it will be about the struggle to find consensus and unity of purpose and less about the force to be deployed in the Baltic states.

Relationships and issues outside the alliance play out between alliance member states – often unpredictably. For example, the stalemate in Cyprus influenced how Greece and Turkey voted for decades, frequently undermining solidarity or blocking initiatives that might seem to favour one nation over another. The reality is that upheavals caused by events outside of NATO dominated the summit, and will continue to do so for some time to come. Chief among these was Brexit and the U.K. leadership upheaval.

These are the hidden perils that the NATO summit revealed.

When Foreign Affairs Minister Stéphane Dion said that it was “terribly unfortunate” that Canada had to send troops to Latvia instead of using them elsewhere, he was not only reflecting his own government’s ambivalence, but the disunity amongst allies.

When Germany’s Angela Merkel appeared resolute on sanctions and deterrence against Russia (a policy shaped, in large, by Britain), she did so despite being under pressure at home for a more accommodating approach, including the relaxation of sanctions sooner rather than later. Other NATO members, such as Italy, Hungary, Turkey and Greece, have also suggested that sanctions have to date been counter-productive. But at least the Russian question offered a thin veneer of unity to observers of the summit.

Many European leaders are furious with Britain for the outcome of the referendum. Paradoxically, the United Kingdom long advocated for Eastern expansion of the EU and NATO and the EU accession of Turkey, and yet the free flow of Eastern Europeans to work in the United Kingdom and fears of Muslim immigration contributed to the “leave” campaign’s anti-European backlash.

It cannot have been simply co-incidental that in the days following the Brexit referendum, Turkey’s President Recep Tayyip Erdogan apologized to Russia for the downing of a Russian fighter nearly a year ago, which was accompanied with warm words of a rapprochement. Days later, Mr. Erdogan, in a widely reported speech, characterized Europeans (and the EU) as Islamophobes – a direct consequence of the rhetoric used by the leave campaigners over the migrant crisis. Finally, Turkey announced that it would strategically cooperate with Russia in the fight against Syria.

It is hard to believe that Turkey’s impressions and grievances with the EU will not impact its positions on various alliance initiatives. Turkey’s call for more anti-terrorism measures were completely eclipsed by the Baltic force announcements.

But it isn’t just Turkey. France, Germany and other EU nations have made clear that there will be no free lunch for a post-EU Britain. The nations sitting around the NATO table, with the exception of a few, most notably Canada, the U.S. and Turkey, are EU members – frictions at one table carry over to the other.

The U.S. presidential election will have an impact on NATO’s future as well. There have been increasing calls on both sides of the U.S. political divide for NATO allies to do more to share greater financial and operational burdens of the alliance. Barack Obama’s call for “more Canada” was the politest manifestation of the new mood in the U.S., which is not confined to the Democrats. A Donald Trump presidency would not be so polite, and perhaps more willing to measure U.S. participation in the alliance as a profit/loss argument.

Either way, for Canada – diplomatically and militarily – these will be difficult circumstances to navigate. Unfortunately, there seems to be little in the ongoing defence policy review to suggest that these fissures in the western alliance are being considered.

Canada will certainly try to maintain alliance solidarity – NATO has been a pillar of our security for decades. If, however, NATO becomes collateral damage to the frictions within the European Union, Canada would be wise to tighten links on a nation-to-nation basis with traditional allies. As a consequence, we will also have to shoulder a greater burden for our own defence than we have in past.

George Petrolekas served with the military in Bosnia, Afghanistan and NATO and is a fellow with the Canadian Global Affairs Institute.

On today's Global Exchange Podcast, CGAI Vice President Colin Robertson sits down with CGAI Fellow Sarah Goldfeder and CGAI Advisory Council Member Laura Dawson to discuss last week's midterm election in the United States. Join Colin, Laura, and Sarah as they debate the implications of the 2018 U.S. midterm on the agenda of Donald Trump, the effect a Democratic House of Representatives will have on Canada, as well as what the election means for bilateral relations moving forward.